Fundamentals about onset and progressive disease character of type 2 diabetes mellitus

ResearchGate is a world wide web for scientists and researchers to share papers, ask and answer questions, and find collaborators. As one of the more than 15 million members, the author uploads research output and reads and responds to some of the questions raised, which are related to type 2 diabetes. In that way, he noticed a serious gap of knowledge of this disease among medical professionals over recent decades. The main aim of the current study is to remedy this situation through providing a comprehensive review on recent developments in biochemistry and molecular biology, which can be helpful for the scientific understanding of the molecular nature of type 2 diabetes. To fill up the shortcomings in the curricula of medical education, and to familiarize the medical community with a new concept of the onset of type 2 diabetes, items are discussed like: Insulin resistance, glucose effectiveness, insulin sensitivity, cell membranes, membrane flexibility, unsaturation index (UI; number of carbon-carbon double bonds per 100 acyl chains of membrane phospholipids), slow-down principle, effects of temperature acclimation on phospholipid membrane composition, free fatty acids, energy transport, onset of type 2 diabetes, metformin, and exercise. Based on the reviewed data, a new model is presented with proposed steps in the development of type 2 diabetes, a disease arising as a result of a hypothetical hereditary anomaly, which causes hyperthermia in and around the mitochondria. Hyperthermia is counterbalanced by the slow-down principle, which lowers the amount of carbon-carbon double bonds of membrane phospholipid acyl chains. The accompanying reduction in the UI lowers membrane flexibility, promotes a redistribution of the lateral pressure in cell membranes, and thereby reduces the glucose transporter protein pore diameter of the transmembrane glucose transport channel of all Class I GLUT proteins. These events will set up a reduction in transmembrane glucose transport. So, a new blood glucose regulation system, effective in type 2 diabetes and its prediabetic phase, is based on variations in the acyl composition of phospholipids and operates independent of changes in insulin and glucose concentration. UI assessment is currently arising as a promising analytical technology for a membrane flexibility analysis. An increase in mitochondrial heat production plays a pivotal role in the existence of this regulation system.     

CD44基因多态性与宫颈癌及非小细胞肺癌的相关性

背景与目的：CD44分子是众多肿瘤细胞的标志分子，其表达水平与肿瘤细胞的恶性程度有关。该研究探讨CD44基因中的单核苷酸多态性（single nucleotide polymorphism，SNP）位点与云南汉族人群宫颈癌和非小细胞肺癌（nonsmall cell lung cancer，NSCLC）易感性的相关性。方法：选取了CD44基因中的两个SNP位点rs13347和rs8193，采用TagMan基因分型的方法，分析这两个多态性位点在497例宫颈癌患者和500例健康对照个体以及483例NSCLC患者和471例健康对照个体中的分布特征，并分析CD44基因中的多态性位点与云南汉族人群宫颈癌和NSCLC的相关性。结果：rs13347和rs8193位点等位基因和基因型在宫颈癌组和对照组中的分布频率的差异无统计学意义（P>0.05）。而在NSCLC组和对照组的比较中：rs13347和rs8193位点等位基因在NSCLC组和对照组中的分布频率的差异有统计学意义（P=0.020和P=0.004）；这两个位点基因型在NSCLC组和对照组中分布频率的差异有统计学意义（P=0.027和P=0.020）；其中rs13347位点等位基因C在NSCLC组中的分布频率显著高于对照组，可能是NSCLC发生的风险因素（OR=1.250，95% CI：1.035～1.509），rs8193位点等位基因C在对照组中的分布频率显著高于NSCLC组，可能是NSCLC发生的保护性因素（OR=0.768，95%CI：0.641～0.921）。单倍型分析结果显示，rs13347C-rs8193T和rs13347T-rs8193C在NSCLC组和对照组中的分布频率差异有统计学意义（P=0.003和0.022）；该结果说明单倍型rs13347C-rs8193T可能是云南汉族人群NSCLC发生的风险性因素（OR=1.316，95%CI：1.096～1.579）。结论：CD44基因中的两个SNP位点rs13347和rs8193可能与云南汉族人群宫颈癌发病风险无关，而可能与云南汉族人群NSCLC具有相关性。     

Investigation of non-linear Mate1-mediated efflux of trimethoprim in the mouse kidney as the mechanism underlying drug-drug interactions between trimethoprim and organic cations in the kidney

The purpose of this study was to elucidate the involvement of Mate1 in the tubular secretion of trimethoprim and saturation of Mate1-mediated efflux to address the mechanisms underlying the pharmacokinetic drug interactions with trimethoprim. Trimethoprim is a more potent inhibitor of MATE2-K than MATE1 with K_i values (μM) of 0.030–0.28 and 2.4–5.9, respectively. Trimethoprim is a substrate of human MATE1 and MATE2-K with K_m values of 2.3 ± 0.9 and 0.018 ± 0.004 μM, and mouse Mate1, but not human OCT2, mouse Oct1 and Oct2. Pyrimethamine significantly reduced the renal clearance (CL_R) of trimethoprim (mL/min/kg) from 40.0 ± 5.1 to 20.1 ± 3.7 (p < 0.05). Trimethoprim was given to mice at three infusion rates (150, 500, and 1500 nmol/min/kg). Together with an increase in the plasma concentrations of trimethoprim, the CL_R (mL/min/kg) of trimethoprim decreased to 25.9 ± 3.2, 13.5 ± 5.7, and 8.92 ± 1.50 at the respective rates. Trimethoprim decreased the CL_R of rhodamine 123 in an infusion rate-dependent manner: 11.5 ± 1.3 (control), 5.17 ± 1.55, 1.31 ± 0.50, and 0.532 ± 0.180. These results suggest that Mate1 mediates the tubular secretion of trimethoprim, and at therapeutic doses, MATEs-mediated efflux can be saturated, and thereby, cause drug interactions with other MATE substrates.     

Brain serotonin transporter binding in non-depressed patients with Parkinson's disease

Early post-mortem data suggest that damage to brain serotonin neurones might play a role in some features (e.g., depression) of Parkinson's disease (PD). However, it is not known whether such damage is a typical characteristic of living patients with PD or whether the changes are regionally widespread. To address this question we measured, by positron emission tomography imaging, levels of the brain serotonin transporter (SERT), a marker for serotonin neurones, as inferred from binding of [¹¹C]-3-amino-4-(2-dimethylaminomethyl-phenylsulfanyl)-benzonitrile (DASB), a second generation SERT radioligand, in subcortical and cerebral cortical brain areas of clinically advanced non-depressed (confirmed by structured psychiatric interview) patients with PD. SERT binding levels in PD were lower than those in controls in all examined brain areas, with the changes statistically significant in orbitofrontal cortex (−22%), caudate (−30%), putamen (−26%), and midbrain (−29%). However, only a slight non-significant reduction (−7%) was observed in dorsolateral pre-frontal cortex, an area implicated in major depression. Our imaging data suggests that a modest, regionally widespread loss of brain serotonergic innervation might be a common feature of advanced PD. Further investigation will be required to establish whether SERT binding is more or less decreased in those patients with PD who also have major depressive disorder.     

Further evidence of dopamine transporter dysregulation in ADHD: a controlled PET imaging study using altropane.

BACKGROUND: The dopamine transporter (DAT) is known to be a key regulator of dopamine, and recent studies of genetics, treatment, and imaging have highlighted the role of DAT in attention-deficit/hyperactivity disorder (ADHD). The findings of in vivo neuroimaging of DAT in ADHD have been somewhat discrepant, however. METHOD: Dopamine transporter binding was measured using a highly selective ligand (C-11 altropane) and positron emission tomography (PET). The sample consisted of 47 well-characterized, treatment-na?ve, nonsmoking, non-comorbid adults with and without ADHD. Additionally, control subjects had few symptoms of ADHD. RESULTS: Results showed significantly increased DAT binding in the right caudate in adults with ADHD compared with matched control subjects without this disorder. CONCLUSIONS: These results confirm abnormal DAT binding in the striatum of adults with ADHD and provide further support that dysregulation of DAT may be an important component of the pathophysiology of ADHD.     

湖北地区汉族变应性哮喘患儿Tim-3启动子区基因多态性研究

目的 探讨湖北地区汉族儿童T细胞免疫球蛋白黏蛋白域蛋白．3（Tim-3）启动子区1541位C〉T和574位G〉T单核苷酸变异及其与变应性哮喘易感性之间的关系。方法 分别采用聚合酶链反应．限制性片段长度多态性（PCR-RFLP）和引物特异PCR-核酸序列测定技术检测湖北143例哮喘患儿和72名健康儿童Tim-3启动子区1541位C〉T和574位G〉T单核苷酸变异，讣算基因型和等位基因频率。结果 湖北地区健康儿童Tim-3启动子区1541位C／C、C／T和T／T基因型频率分别是0．961、0．039和0，而哮喘患儿频率分别为0．935、0．065、0，其基因型频率与对照组差异无统计学意义（r=0．3825，P=0．5362）；湖北健康儿童中Tim-3启动子区574位G／G、G／T和T／T基因型频率分别为0．992、0．008和0，而哮喘患儿频率分别为0．941、0．059、0，两组基因型频率差异有统计学意义（χ^2=4．134，P=0．042）。结论 湖北汉族儿童Tim-3启动子区存在多态性变异，其中574位G〉T多态性可能与湖北汉族儿童变应性哮喘易感性有关。     

Monoclonal antibody production to human and bovine 2′:3′-cyclic nucleotide 3′-phosphodiesterase (CNPase): high-specificity recognition in whole brain acetone powders and conservation of sequence between CNP1 and CNP2

Monoclonal antibodies against human and bovine 2′:3′-cyclic nucleotide 3′-phosphodiesterase (CNPase) were generated by fusing FOX-NY myeloma cells with spleen cells from RBF/Dn mice previously immunized with the purified brain antigens. The enzyme isolated from bovine brain was quite basic, with an isoelectric point of 9.71 and both the bovine and human enzymes consisted of a closely spaced doublet at approximately 44 and 46 kDa on SDS-PAGE. Six monoclonals were identified as strongly recognizing the enzyme on both ELISA plates and on immunoblots of whole brain protein. Four monoclonals very weakly cross-reacted with guinea pig myelin basic protein. In contrast with two previous reports, some of our monoclonal antibodies did immunostain 2 or 3 protein bands in peripheral nerve, two bands closely corresponding to those immunostained in central nervous system (CNS) myelin, the Wolfgram protein fraction and in acetone powders of whole brain. Each of the 6 monoclonals reacting strongly on immunoblots recognized the enzyme in from 2 to 5 of the species examined (human, bovine, rat, mouse and rabbit). In addition, all 6 monoclonals that immunostained the enzyme in whole brain, myelin and Wolfgram protein immunoblots recognized both CNP1 (44 kDa) and CNP2 (46 kDa). The two closely spaced protein bands observed on SDS-PAGE and previously stained on immunoblots of CNS CNPase using polyvalent rabbit anti-bovine CNPase antisera, and now different monoclonal antibodies, appear to be immunologically related and to contain highly conserved sequences.     

腺嘌呤核苷酸载体的功能和表达与心力衰竭

腺嘌呤核苷酸载体（ANT）是一种位于线粒体内膜上的转运蛋白，它在组织细胞能量产生和消耗的耦联中起关键性作用。作者就ANT的功能和表达情况及其与心力衰竭之间的关系作一综述。